Réponse :
Explications étape par étape
Bonsoir
101^2
= (100 + 1)^2
= 100^2 + 2 x 1 x 100 + 1^2
= 10000 + 200 + 1
= 10201
1001^2
= (1000 + 1)^2
= 1000^2 + 2 x 1000 x 1 + 1^2
= 1000000 + 2000 + 1
= 1002001
99^2
= (100 - 1)^2
= 100^2 - 2 x 100 x 1 + 1
= 10000 - 200 + 1
= 9801
401 x 399
= (400 + 1)(400 - 1)
= 400^2 - 1^2
= 160000 - 1
= 159999
45 x 35
= (40 + 5)(40 - 5)
= 40^2 - 5^2
= 1600 - 25
= 1575
